Power supply device



July 2, 1940. H. RINIA El AL 2,206,123

POWER SUPPLY DEVICE Filed April 28, 1937 2 Sheets-Sheet 1 INVENTORS HE RRE R/N/A AND/EMWMDR VEA/ W ATTO R N EY July 2, 1940. H. RINIA El AL POWER SUPPLY DEVICE Filed April 28, 1937 2 Sheets-Sheet 2 INVENTORS HERRE RlN/A ATTORNEY Patented July 2, 1940 POWER SUPPLY DEVICE Herre Rinia and Adrianus J. Heins van der Ven, Eindhoven, Netherlands, assignors, by mesne assignments, to Radio Corporation of America, New York, N. Y., a corporation of Delaware Application April 28,

In Germany Claims.

The invention concerns a circuit arrangement for keeping constant the voltage at the terminals of an electric device which is supplied from a source of current of variable voltage. It is known 5 to connect between the source of current and the load, namely in the positive conductor, a controlled tube whose internal resistance is caused to vary in accordance with the voltage variations at the load. It is not possible, however, to obtain in this way at the terminals of the load a voltage which is sufflciently constant for any purpose; one is therefore compelled to have the controlled tube preceded by a second tube which amplifies the voltage variations set up at the load. This tube may be connected as a resistance amplifier while the cathode is to be connected to the negative terminal of the source of voltage. The anode is connected to the grid of the control tube and also, via a resistance, to the positive terminal of the load so that no particular source of anode current for the amplifying tube is required. In this case there arises, however, the difiiculty that in the case of a high conductivity of the control tube the amplifying tube is almost completely blocked so that it functions badly in this region.

According to the invention, this drawback is removed by connecting the anode of the amplifying tube not only to the grid of the control tube but also to a point of a resistance which shunts the latter tube.

Figure 1 represents, by way of example, one mode of realization of a circuit arrangement according to the invention with reference to which the invention will be explained more fully.

Figures 2 to 5 represent further developments.

In the drawings, I denotes a tube connected in series with a load connected between terminals 4 and 5. It is assumed that the source of supply current which is connected between the terminals 2 and 3 furnishes direct current. The tube 1 is constructed as a triode whose grid charge depends on the feed voltage across the terminals 4 and 5 in such marmer that the internal resistance increases when the feed voltage increases and decreases when said voltage decreases.

The feed voltage across the terminals 4 and 5 7 may vary in consequence of two causes viz. firstly 50 due to the voltage variations of the source of 1937, Serial No. 139,344

April 28, 1936 current between the terminals 2 and 3 and secondly due to the variation of the current taken up by the device connected between 4 and 5. If the grid were connected to the negative conductor, of the mains, the following relations would be valid:

Q dE becomes approximately equal to 9G and approximately equal to i SG If the mains have an internal resistance Rn, the mains voltage is decreased, in the case of a current increase of Ai, by an amount 1 AE-gaR The result is consequently a total variation of the feed voltage with varying current intensity:

1 1 3a gGR|| The mounting of the tube between the terminals 4 and 5 has, however, the drawback that in the case of a high current intensity the control is bad because in this case the amplifying tube 6 is almost completely blocked. As indicated in the drawings, the anode current is therefore taken from a resistance which shunts the tube and which consists of parts I and 8. If the resistance values of I and 8 are n and r2 respectively, the control tube has an apparent amphfication factor obtained. Besides, part of the resistance by which the tube I is shunted, may be constituted by a. glow-discharge tube with the result that 9 becomes still more favorable.

A battery 9 serves to give the grid the correct bias voltage. With the circuit-arrangements shown in Figures 1-4, the battery voltage must be at least equal to the voltage V. It is possible however to connect the grid to a point of a potentiometer connected between 4 and 5, m which event a lower battery voltage may be chosen. The exactness of control is reduced, however to 'the same extent.

As the amplifying tube brings about reversal of phase complete neutralization of the voltage variations is possible. Figure 2 represents a circuit arrangement by means of which such neutralization may be obtained. In this case the grid of the amplifying tube is also connected to a point of a resistance which shunts the tube I and which consists of two parts ill and II. If Ill has a value 1': and i I a value n,

a. dE becomes equal to 0 if T3 L Ta+' '4 0 As shown in Figure 3, the grid may also be connected to a point of the resistance i2 which bridges the terminals 2 and 3, owing to which the same eifect is obtained as in Fig. 2.

A circuit arrangement wherein neutralization,

may be obtained, is shown in Figure 4, wherein a resistance I3 is connected into the negative conductors and the grid of the tube 6 is connected to a point of this resistance in such manner that the grid voltage is influenced in addition by the current variations. If the resistance values of i3 and M are denoted by n; and re respectively, one obtains It is evident that instead of a single control tube l, a plurality of such tubes may be connected in parallel. Furthermore, for the amplifying tube 6 should preferably be utilized a multig'rid tube as shown in Figure 5. The tube 6 which is represented in this figure is a tube having a screen grid which is connected to the common point of the resistances l1 and I8 connected in series between the terminals 4 and 5.

Figure 5 further represents a slightly modified circuit arrangement for the source of voltage 9 which furnishes the bias voltage. Said source 9 is connected in series with resistances I5 and it between the terminals 4 and 5. The advantage of this circuit arrangement is that a single source of voltage may be utilized simultaneously for a plurality of control installations. The source of voltage also furnishes current so that as such should preferably be chosen, instead of a battery, a feeding device comprising a rectifier whose voltage should preferably be kept constant again with the aid of a control device as set out hereinbefore.

We claim:

1. A circuit arrangement for keeping a substantially constant voltage between the terminals of an electric device supplied from a source of current of variable voltage, comprising an electronic tube provided with an anode, a cathode and a grid electrode, said tube being connected in series with said device, resistance means connected between the anode and cathode-of said tube, a connection between the grid electrode of the tube and an intermediate point of said resistance means whereby a voltage is applied to said electrode which is intermediate the voltage between the cathode and anode of the tube, means for supplying a grid voltage to said tube which depends on the feed voltage of the device, said last'named means comprising a second tube arranged to amplify the voltage variations, said tube being provided with an anode, a cathode and a control grid, means for connecting the anode of the second tube to the grid of the first tube and to a point of said shunting resistance means.

2. In a. circuit arrangement as described in the next preceding claim, a second resistance means in shunt with the first named tube and means for connecting the grid electrode of the second tube to a point of said second resistance means.

3. A circuit arrangement for keeping a substantially constant voltage between the terminals of an electric device supplied from a source of current of variable voltage comprising an electronic tube having an anode, a cathode and a grid electrode, said tube being connected so that its space path is in series between said source of current and said electric device, resistance means in shunt with said tube, means for connecting said grid electrode to an intermediate point of said resistance means to thereby impress upon 'said grid electrode a voltage which is intermediate the voltage between the cathode and anode of the tube and means for supplying a grid voltage to said tube which depends upon the feed voltage of the device comprising a second tube connected in shunt with said electric device and arranged to amplify the voltage variations, said second tube having an anode, a cathode and a control grid and means for connecting the anode of the second tube to the grid of the first tube and to a point of said first named shunting resistance means.

4. In an arrangement as described in the next preceding claim, resistance means shunted across the source of current and means for connecting the grid of said second tube to a point of said P resistance.

5. A voltage regulator device having a pair of input terminals and a pair of output terminals, an electronic tube provided with an anode, a cathode and a control electrode, a connection between one of the input terminals and the anode, a connection between one of the output terminals and the cathode, a connection including a pair of resistance elements between said input terminal and output terminal, means for connecting the control electrode to a point of said last named connection which is intermediate said two resistance elements to thereby provide said grid electrode with a voltage which is intermediate the voltage between the cathode and anode of the tube, a second electronic tube provided with an anode, a cathode and a control electrode,

means connecting the anode of said second named electronic tube to the control electrode of the first named tube, a connection between the other input terminal and the other output terminal, means connecting the cathode of the second tube to a point of said connection, and a connection including a source of direct current potential between the grid electrode of the second tube and the first named output terminal.

HERRE RINIA. ADRIANUS J. HEINS VAN DER VEN. 

